Composition for preventing set-offs in printing.



UNIT D STATES PATENT OFFICE.

GEORGE STEELE DUNCAN AND GEORGE HENRY POTTS, OE EDINBURGH,

SCOTLAND, ASSIGNORS TO AMERICAN OFFSET COMPANY, OF YORK, N. Y., ACORPORATION OF NEW YORK.

I COMPOSITION FOR PREVENTING SET-OFFS IN PRINTING.

I Nb. 823,676.

Specification of Letters Patent.

Patented June 19, 1906.

Applicatioufiled August '7, 1905. Serial No. 273,140.

T at whom, it may concern:

Be it known that we, GEORGE STEELE DUN- CAN and GEORGE HENRY PoTTs,subjects of the King of the United Kingdom of Great Britain and Ireland,residing at Edinburgh, Scotland, have invented certain new and usefulImprovements in Compositions for Preventing Set-Oifs in Printing, ofwhich the following is. a specification.

In the specification of application Serial No. 259,37 4 is described aliquid composition to be used for damping the set-ofi rollers inprinting-machines to prevent set-off or transfer of ink from one sheettoanother or from one side to the reverse side of a sheet in printing.

Our present invention has for its object the provision of a liquidcomposition to be used 1n the same manner as the liquid composition thesubject of the said application, but differing therefrom in itscomposition and ossessing especial advantages if some or a of the' work1s to be done on high-speed rotary machines.

The constituents of the liquid composition the subject of our presentinvention are palmoil or whale-oil, or both, lard-oil or cocoanutoil, orboth, with or without all or any of the following oils: sperm-oil,tallow-oil, cottonseed oil, and soap, preferably brown Windsor soap,spirits of wine, naphtha, and turpentine, the two last as ordinarilyused by printer's. Whale-oil is the equivalent of almoil for usein ourcomposition. Similar y, cocoanut-oil is the equivalent of lard-oil.Where one is mentioned, the equivalent may be used or a mixture of theequivalent oils. In like manner sperm, tallow, and cotton-seed oil areequivalent, and either or all may be used with like result in ourcomposition.

The best proportions are the following:-

The volume of the palm-oil or whale-oil or of the mixture of both shouldbe about'the same as the volume of the lard-oil or cocoanut-oil or ofthe mixture of both, and the volumeof each of the oils-sperm, tallow,and cottonseed oils-if used should not exceed the half of the volume ofthe palm or whale oils or of the mixture of these two oils. The soapthese two.

the volume of each should be rather more than half, say, two-thirds, thevolume of the palm or whale oils or of the mixture of these two. Thenaphtha should be twice as much, by volume, as the turpentine and may beeven appreciably more than twice such volume. It is preferable to usesome sperm-oil to assist admixture. If cotton-seed oil is dispensed withor its volume diminished, the volume of the lard-oil or cocoanut-oil orof the mixture of these two should be roportionately increased. Thevolumes 0 such of the abovementioned oils as are solid at ordinary temperatures are measured after by entle heat mg the particular oils havebeen iquefied.

As it 1s desirable to ap ly heat to effect as good an admixture of tilesoap as possible and accordingly to defer adding the naphtha until aftersuch heating, we have found it preferable, especially if the heating isdone,

"for example, over an open fire, to employ the method described in thespecification of the said application in effecting the mixture of thecomponents of the liquid composition the subject of our presentinvention. Instead of naphtha'benzin may be used, but naphtha ispreferable.

Having now described our invention, what we claim,'and desire to secureby I etters Patent of the United States, is.

1. A composition for preventing set ofi 'comprisin palm-oil, lard-oil,soap, spirits of wine, nap tha, and turpentine.

2. A composition for preventing set-off comprising palm-oil, lard-oil,sperm-oil, soap, spirits of wine, naphtha and turpentine.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

GEORGE STEELE DUNCAN. GEORGE HENRY POTTS.

Witnesses:

MARY MCOREDIE, WALLACE CEANsToN FALRWEATHER.

NEW

